KR100264708B1 - Television receiver with teletext decoder - Google Patents

Abstract

A television receiver including a teletext decoder (3) is adapted to search and display a teletext subtitling page in response to a display command (71) supplied for this purpose. If there are more subtitling pages, their page numbers are stored in a memory (12) from which they can be selectively requested. For each receivable television station the page number used by said station is fixed in a non-volatile memory (12). <IMAGE>

Description

Television receivers including teletext decoders

1 is a general structural diagram of a television receiver including a teletext decoder in accordance with the present invention.

2 is a possible format diagram of a teletext data packet processed by the teletext decoder shown in FIG.

3 is a diagram showing possible divisions of the memory shown in FIG.

4 through 9 are flow charts of the control program executed by the control circuit shown in FIG.

* Explanation of symbols for main parts of the drawings

1: antenna 2: tuning and demodulation circuit

3: video signal processing circuit 4: teletext decoder

5: multiplexer 6: display screen

8: receiver circuit 9: control circuit

[Background of invention]

The present invention relates to a television receiver comprising a teletext decoder. Such a receiver can be a television device, but can also be a video recorder, for example.

[Description of the Prior Art]

Television receivers comprising a teletext decoder are generally known. Depending on the program provided by the television station, various information such as news, weather forecasts, TV programs, sports results, exchange rates, local information, entertainment information, and the like can be obtained from the television receiver. This information is received in a plurality of teletext pages and transmitted by a television broadcaster in the form of a cycle series.

In particular, teletext offers the possibility of functionally attaching subtitles to television programs. For this purpose, subtitles are accommodated in teletext pages. This subtitle contains one page of lower test rows. The part of the text line to be displayed is indicated by the box code inserted on both sides. It also sets a control bit (subtitle indicator) that forms part of the teletext page. In a teletext decoder, the control bit means that only a part should be displayed on the page between the box codes. The rest of the display screen shows the television program. Necessary synchronization with the television program is achieved by transmitting the teletext page with the actual subtitle every exact time, thereby stopping the series of circuits for a while.

The user requests the access to the subtitle service by entering the page number of the subtitle page. This raises the problem that, for example, the user must know the page number from a TV program guide in a television program or from an audiovisual broadcast means. If the user does not know the page number, they cannot access the subtitle service. Fortunately, almost all stations use fixed page numbers for teletext subtitles. However, since different countries use different numbers, the problem is not solved for users who can receive television programs from these different countries. For example, the UK currently uses page 888 and Germany uses page 150. There is a TV manufacturer that provides a device with a subtitle key, which automatically selects the page number of the subtitle page. This simplifies the operation of the subtitle. However, the relevant page number is fixed on the device and supplied only to one country, and its validity is lost if that country introduces another teletext page for the subtitle.

Another problem arises when a plurality of subtitle pages are transmitted by one broadcaster. For example, there are subtitles for television programs in various languages, the native language (commonly used for the benefit of the poor), and other languages (for example, for minorities who speak a foreign language). Another example is a situation such as, for example, what happens in the Netherlands where three national television stations transmit a common file of teletext. In this case, the subtitle page for the television program of the NL1 broadcasting station is the file page 199, the subtitle page for the television program of the NL2 broadcasting station is the file page 299, and the subpage page for the television program of the NL3 broadcasting station is the file page 399. The user must remember a plurality of page numbers and be aware of which broadcasting station he is tuning to.

[Object and Summary of the Invention]

It is an object of the present invention to provide a television receiver comprising a teletext decoder which solves the above object from the user's point of view. For this purpose, the receiving apparatus according to the present invention is characterized in that it comprises recognition means for identifying the transmitted teletext subtitle page, and selection means for selecting and displaying the determined subtitle page in response to a display command. As a result, when the user generates a related display command, the subtitle page is automatically displayed. The command is obtained, for example, by pressing a subkey or selecting from the operation menu. The user does not need to know the page number and does not have to enter it. There is no difference for a user whether the user's receiver is tuned to which station and whether that station uses or does not use a fixed page number for the subtitle.

In a possible embodiment of the receiver according to the invention, the recognition means detects a subtitle indicator of the transmitted teletext pages, fixes the corresponding page number based on the detection, and for the purpose of selection The page number is stored in the memory 121. In the presence of a subtitle indicator, the "scanning" of the transmitted page takes some time and can occur in the normal operating state of the receiver. Because the page number is remembered, the subtitle page is acquired immediately as soon as the subtitle key is pressed.

If it is necessary to use a plurality of subtitle pages, these subtitle pages are selectively read out from the memory and supplied to the teletext decoder of another embodiment. When the absent key is first pressed, for example, page 199, that is, the subtitle page of the NL1 station, is generated. When the user watches the NL3 station and recognizes that the subtitle does not belong to the television program, pressing the subtitle key again can obtain page 299 and continue to obtain page 399 with the desired subtitle.

In another embodiment of the receiver, the recognizing means assigns a priority indicator to the page number of the subtitle page having a predetermined repetition frequency. The selecting means first supplies the page number having the indicator first to the teletext decoder. The reason for this is as follows. When there is no subtitle in the television program, the broadcaster nevertheless sends a relevant text page. But only once in the series. At this point, the page has a static content, an announcement of the next television program that will have a subtitle. If there is only a subtitle in the program of the NL3 station, the receiver actually displays the actual subtitle page 399 as the first page, because the static subtitle pages 199 and 299 are only received once in a traversal cycle, for example, 30 seconds. . The repetition frequency can be determined by measuring the number of consecutive repetitions of the page at predetermined time intervals.

In another embodiment of the receiver, the selection means stores the page number of the displayed subtitle page in another memory in response to the storage signal and first supplies the page number to the teletext decoder in response to the display command. In a preferred embodiment, the memory is configured to be automatically performed as soon as the subtitle page is displayed for at least a predetermined period of time. For example, if a television program has several language subtitles, and the user selects his or her native language by observing another language for only a short time, that page number with that native language is later called as the first page according to consecutive subtitle requests do. The page number is preferably stored separately in the nonvolatile memory at each broadcasting station. In this way, a television receiver, which is automatically suitably programmed for each broadcasting station, is obtained in accordance with the owner's observation behavior.

EXAMPLE

Figure 1 shows the general structure of a TV receiver comprising a teletext decoder according to the invention. The transmitter signal received at the antenna 1 is provided to a conventional tuning and demodulation circuit 2. The composite video signal CVBS obtained from the selected TV program is provided to the video signal processing circuit 3 and the teletext decoder 4. In normal TV operation, the state of the receiver color signal R′G′B ′ is provided to the display screen 6 via the multiplexer 5 in the video signal processing circuit 3 so that the user can receive the received TV program. I can see it. In a teletext operating state that can be called by the user, the color signal RGB from the teletext 3 is displayed on the display screen. The multiplexer 5 is controlled by the blanking signal FBL generated by the teletext decoder 4. The TV receiver further includes an audio receiving and reproducing unit (not shown).

The operation instruction given by the user is generated in the remote control unit 7 and applied to the control circuit 9 via the receiver circuit 8. The remote control unit 7 has a subtitle key 71. In general, the control circuit 9 is a microprocessor. The teletext decoder 4 is connected to the microprocessor by a command bus 10. The interface 11 allows the microprocessor to tune the receiver to a broadcast station, control image brightness and volume, etc., and is also connected to the command bus. This is shown by the appropriate numeral in the figure. The memory 12 is also connected to the microprocessor 9.

The composite video signal CVBS has one or more picture lines with teletext information in the field flyback interval. As shown in FIG. 2, these picture lines have 45 bytes of data packets each consisting of 8 bits. The first two bytes with a fixed value of 1010..10 are called "clock run-in" and are indicated by CRI in the figure. The third byte is the "framing code" (FC) and also has a fixed value. The next two bytes contain a magazine number (M) and a row number (R). The remaining 40 bytes depend on the value of the row number (R). As shown in Fig. 2 (a), if the line number has one of the values 1 to 23, 40 bytes are displayed on the display screen indicating 40 lines of text. As shown in Fig. 2 (b), if the row number has a value of 0, the data packet includes the page header of the teletext page. This page header starts with a portion containing a page number bit (PAG), a sub page number (SUBPAG) and a number of control bits (CB). The remaining parts represent letters and are displayed on the display screen. Page transfer means starting with the page header and having a series of related text lines. The page number of the page is formed of a magazine number (M) and a page number bit (PAG) of the page header. The page number has 3 digits and ranges from 100 to 899. A series of teletext pages are sent in repetitive cycles. The duration of the cycle depends on the page number transmitted, for example 30 seconds.

The teletext decoder 4 is, for example, a decoder of the Philips SAAS246 type which is commercially available. The decoder has a plurality of acquisition circuits, each of which searches for a teletext page with the requested page number and stores the page in a page memory (not shown). A decoder characteristic of this type is that a “don't care” page number can be provided to the acquisition circuit, which means that the decoder sends the received page to the page memory at that moment, regardless of the page number. It means to remember. Another feature of this type of decoder is that the page memory can be read and written by the microprocessor 9 via the command bus 10. In particular, as shown in FIG. 2 (b), data such as the page number and control bits of the received teletext page are read by the microprocessor.

3 shows possible divisions of the memory 12 (see FIG. 1). The memory has a first portion 121 having memory locations listed as 100-899, each of which corresponds to a page number in the range of 100-899. Each storage position i has a flag bit P (i) and S (i) and a counter C (i). The importance of these will be described later. The second portion 122 of the memory includes a storage location in which the page number PAG (Z) can be stored in each of the receivable transmitters Z ((Z = 1, 2 ... N)). Since the second part of this memory 12 is nonvolatile, the stored data is preserved even after the receiver is switched off.

The operation of the TV receiver shown in FIG. 1 is based on the control program executed by the microprocessor 9. As shown in FIG. 4, this control program includes an initialization program 30, a recognition program 40, and a selection program 50. As shown in FIG. The initialization program 30 is executed after the receiver and the transmitter are tuned. Recognition program 40 is executed after each vertical flyback period of the TV signal. For this purpose, the microprocessor receives the vertical synchronizing pulses V from the video signal processing circuit 3 (shown in FIG. 1). When the user command C is received from the remote control unit 7, the selection program 50 is executed.

5 shows the initialization program 30 in the form of a flowchart. The program includes a step 31 in which a "money care" page number XXX is provided to the first acquiring circuit ACQ1 of the teletext decoder. Then, in step 32 the flag bits P (i) and S (i) are reset in the memory 121 (shown in FIG. 3), and the counter C (i) is set to zero. This is provided for all memory locations 100 ... 899. In step 33 an initial value P = 100 is assigned to the index p. Its importance will be described later.

6 shows the recognition program 40 in the form of a flow chart, which is executed after each vertical field flyback period. In step 41 it is checked whether a new teletext page has been received during the field flyback period. If so, this is the case where the page header has been received and stored by the teletext decoder during the flyback period. In step 42, the page number provided in the page header is read and assigned to the index "pgnr". In order to indicate that the page is present in the transfer cycle, in step 43 a corresponding flag bit P (pgnr) is set in memory 121 (shown in FIG. 3). Then, it is checked in step 44 whether the received page is a subtitle page. For this purpose, the microprocessor reads the sub-bits SBT supplied in the page header to form the control bit CB portion shown in FIG. 2 (b). If the page is a subpage, in step 45 the flag bit S (pgnr) is set, and in step 46 the counter C (pgnr) is raised by one.

As will be clear, a table P is formed in the memory 121 in this manner, and for each page number, this table P indicates whether a corresponding teletext page is provided in the transfer cycle, and the table S is formed, and this table S indicates whether or not a subtitle page exists for each page. The counter C also records the number of times the subtitle page has been received. An increase in counter C may not be necessary in a simple embodiment of the recognition program. If desired, the increase in the counter may be limited for a certain period of time, eg 1 minute. For this purpose, a “update” indicator can be used in the form of control bits added to each teletext page.

7 shows the selection program 50 in the form of a flow chart, which is executed as soon as user command C is received from a remote control unit. In step 51, it is checked whether the key has been pressed by the user. In particular, it is checked whether the user has pressed the subtitle key 71 (see FIG. 1). If the subkey has not been pressed, the selection program is terminated and no further action is performed in connection with the present invention. If it is determined in step 51 that the subtitle key has been pressed, then in step 52 it is checked whether the flag bit S (k) is set. For this purpose, the index P (the initial value 100 received in the initialization program 30) is raised by one until S (P) = 1 or until p exceeds the upper limit 899. In step 53, it is checked whether step 52 remained at P> 899 or S (P) = 1. In the first case, at 54, the user is informed that there is no useful subtitle. In the last case, p denotes the page number of the subtitle page. In step 55 this page number is provided to the second acquiring circuit ACQ2 of the teletext decoder so that the decoder obtains the relevant page again and displays it on the display screen. The display screen shows both television programs and subtitles. The selection program 50 then ends.

If the user presses the subtitle key twice or continuously, the selection program 50 is executed again. In detail, this means that the current subtitle is found and displayed in step 52. For example, when three subtitle pages 199, 299 and 399 appear, it is determined in step 52 that S (199) = 1 and page 199 are displayed after the subtitle key is pressed once. If the subtitle key has been pressed twice, step 52 is executed with P = 199 as the initial value and consequently S (299) = 1 is found and page 299 is displayed. Likewise, page 399 is displayed when the subkey is pressed three times. After the subtitle key is pressed four times, the user is informed that P> 899 and in step 54 no other useful subtitles and / or subtitle modes remain.

8 shows another embodiment of a selection program 50. This embodiment is distinguished from the above embodiment because there are further steps 56 to 58. In step 56 it is checked whether the selection program is initially executed. If executed initially, in step 57 a memory location where counter C (m) has the largest value is searched. In step 58, a page with page number m is obtained and displayed. If the selection program is run twice in succession, another sub-page is selected. Steps 52 to 55 used for this purpose have been described above. In this way, priority is given to the selection of the most frequently received subtitle page. As a result, other possible subtitle pages are called consecutively. In a television station, for example, three subtitle pages 199, 299 and 399 are transmitted, of which 199 and 299 are static subtitle pages and 399 are actually dynamic subtitle pages, when page 399 is the first page when the subtitle key is pressed. Is displayed as.

9 is a flowchart of another embodiment of a selection program 52. This embodiment applies to storing one or more subtitle page numbers PAG (z) for each receivable television transmitter z. For this purpose, the water receiver includes the nonvolatile memory 122 shown in FIG. In step 59 of the selection program, it is checked whether the timer t has reached a predetermined value T. Since the timer has not yet started to operate at first, it is assumed that the timer has not reached the predetermined value. In step 56 it is checked whether the subtitle key was initially pressed to execute the selection program. If the subtitle key is pressed, in step 61 it is checked whether the subtitle page number PAG (Z) of the transmitter z tuned to the receiver is stored in the nonvolatile memory. In step 62 the page is acquired and displayed. If there is no memorized page number or if the selection program is executed twice in succession, the subtitle page found in the recognition program is selected sequentially in the steps 52 to 55 mentioned above. In both cases, the timer t is started continuously in step 63. The timer does not start until the acquired page is actually displayed. Thus, the timer t represents the time during which the user consults the subtitle page. For example, if the time is short because the user searches for useful subtitle pages too quickly, the timer does not reach a predetermined value T. However, for a long time, if the selected subtitle page is observed, the selected page number is clearly associated with the transmitter z tuned to the receiver. Even if the subtitle mode is in this situation, the predetermined page number T is exceeded and the page number referenced at that time is stored in the nonvolatile memory. For this purpose, the associated page number is stored in the position PAG (z) of the nonvolatile memory in step 60.

If the receiver is tuned to the NL3 station and the user finally selects the subtitle page 399 via subpages 199 and 299, page 399 is memorized for the NL3 station. When the user tunes back to the station again, the page is called first as a result. In a similar manner, page 199 is connected to NL1 station and page 299 is connected to NL2 station. In the situation of assigning different page numbers to various languages, the user's favorite language selection is automatically stored in the receiver.

Claims (6)

A television receiver comprising a teletext decoder for selecting and displaying a teletext page, comprising: recognizing means (40) identifying transmitted teletext subtitling pages and the identified subtitle page, display instructions (71). Television selection means (50) for selecting and displaying in response to the &lt; RTI ID = 0.0 &gt; 2. The apparatus according to claim 1, wherein the recognition means (40) detects subtitle indicators of the transmitted teletext pages, fixes a corresponding page number based on the detection, and stores the page number for the purpose of selection. 121) a television receiver. The method according to claim 2, wherein the selecting means (50) selectively stores the page numbers from the memory (121) and stores the plurality of page numbers, and supplies the page numbers to the teletext decoder. Television receiver. 4. The method according to claim 2 or 3, wherein the recognition means 40 assigns a priority indication C to the page number of the subtitle page having a predetermined repetition frequency, and the selection means 50 has the priority indication. And a page number is first supplied to a teletext decoder. The method of claim 2 or 3, wherein the selecting means (50) stores the page number of the displayed subtitle page in another memory (122) in response to a storage signal (59) and stores the page number in response to a display command. A television receiver, which is supplied first to a teletext decoder. 6. A television receiver according to claim 5, wherein said memory signal (59) is formed by displaying a subtitle page for at least a predetermined time period.